A brake shoe pressure control detection system capable of simulating an environment

Abstract

The present application relates to a brake shoe pressure control detection system capable of simulating an environment, which includes a test box, a brake drum, a drive shaft, a drive motor, a speed detector and an angle sensor; the speed detector and the servo cylinder are connected to a master controller, which is configured to control the braking of the servo cylinder and the hydraulic cylinder when the speed detector detects that the rotation speed of the drive shaft reaches a preset value, and release the power transmission from the drive motor to the drive shaft at the same time; the master controller is connected to a timer, which is configured to record the braking time when the rotation speed of the brake drum is zero after being braked; the brake drum is embedded with multiple displacement detectors pointing to the surface of the brake shoe to be tested, and the brake drum is provided with a control mechanism for driving the probes of the multiple displacement detectors to contact the surface of the brake shoe to be tested when the brake drum stops rotating. The present application can perform real-time detection of the braking time and the amount of brake wear of the brake shoe under different working conditions, with higher efficiency and accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of brake system detection, and in particular to a brake shoe pressure control detection system capable of simulating an environment. Background Art

[0002] Brake shoes, also known as brake pads, are friction pairs of drum brakes and are a key component in the braking system. Their main function is to work with the brake drum to slow down or stop the vehicle by generating friction torque. The brake shoe bears the thrust of the actuator, the normal force and tangential force of the brake drum, and the support reaction force, so it needs to have appropriate stiffness. In the design and production of brake shoes, it is necessary to control different braking forces to test the performance of the brake shoes.

[0003] In the related art, a Chinese patent with publication number CN107966292A proposes a brake shoe pressure control detection system that can simulate the environment, including a test box, a hydraulic pipeline, a pneumatic pipeline, and a caliper arranged in the test box. The test box is provided with a humidity adjustment device and a temperature adjustment device. The caliper is connected to a hydraulic cylinder for controlling the two clamping parts of the caliper to be close to each other; the hydraulic pipeline includes a hydraulic container connected to the hydraulic cylinder, a hydraulic detection component for detecting oil pressure, and a first locking valve body for locking the oil pressure of the hydraulic cylinder. The pneumatic pipeline includes a cylinder connected to the hydraulic container, and the cylinder piston rod pushes to control the hydraulic oil in the hydraulic container to flow to the hydraulic cylinder. It can reliably simulate a variety of brake pad working environments with different humidity, temperature and oil pressure, and effectively use it to detect the performance of the brake pad.

[0004] The above-mentioned related technologies have the following defects: Although the working environment of the brake shoe can be simulated with the help of a temperature and humidity adjustment device, the wear degree and braking time of the brake shoe are different under different braking forces, and even under different initial velocities, there are different wear degrees and braking times. Therefore, when evaluating the braking performance of the brake shoe, it is necessary to test and evaluate from multiple aspects. The current related equipment is relatively simple for testing the performance of the brake shoe. Especially when testing the wear degree of the brake shoe, due to the small gap between the brake shoe and the brake drum, the brake shoe needs to be disassembled for testing, which seriously affects the testing efficiency; or the powder worn off the brake shoe is weighed, and the testing accuracy is extremely poor, so it needs to be improved. Summary of the invention

[0005] In order to improve the problem that the existing detection equipment has a single function and is difficult to detect efficiently and accurately when detecting the performance of the brake shoe, the present application provides a brake shoe pressure control detection system that can simulate the environment.

[0006] The present application provides a brake shoe pressure control detection system capable of simulating an environment, which adopts the following technical solutions:

[0007] A brake shoe pressure control detection system capable of simulating an environment, comprising a hydraulic cylinder for controlling a brake shoe to be tested, a hydraulic pipeline connected to the hydraulic cylinder, and a servo cylinder for outputting or releasing hydraulic oil in the hydraulic pipeline to the hydraulic cylinder, and also comprising a test box, a temperature and humidity regulating device, and a base for mounting the brake shoe to be tested, the base being placed in the test box, a brake drum used in conjunction with the brake shoe to be tested being rotatably mounted in the test box, a drive shaft extending to the outside of the test box being coaxially fixedly connected to the brake drum, a drive motor for driving the drive shaft to rotate, a speed detector for detecting the rotation speed of the drive shaft, and an angle sensor for detecting the rotation angle of the drive shaft being arranged outside the test box;

[0008] The speed detector and the servo cylinder are connected to a master controller, and the master controller is configured to control the servo cylinder to supply hydraulic oil of a set oil pressure to the hydraulic cylinder and release the power transmission from the drive motor to the drive shaft when the speed detector detects that the rotation speed of the drive shaft reaches a preset value;

[0009] The master controller is also connected to a timer, which is configured to record the braking time from the start of the controlled operation of the servo cylinder to the time when the rotation speed detector detects that the rotation speed of the drive shaft is zero;

[0010] The brake drum is embedded with multiple displacement detectors pointing to the brake shoe surface to be tested, and the brake drum is provided with a control mechanism for driving the probes of the multiple displacement detectors to contact the brake shoe surface to be tested when the brake drum stops rotating.

[0011] Furthermore, a detection groove is penetrated through the inner arc side of the brake drum, and a mounting seat connected to the detection groove is fixedly connected to the outer arc side, a mounting platform is movably arranged in the mounting seat, and a plurality of displacement detectors are fixedly connected to the mounting platform along the width direction of the brake shoe to be tested, and a control component is arranged in the mounting seat for driving the mounting platform to move away from the middle of the brake drum when the brake drum rotates, and a reset component is arranged in the mounting seat for driving the mounting platform to reset when the brake drum stops rotating.

[0012] Furthermore, the control component includes a guide member and a centrifugal member, the guide member is used to limit the multiple displacement detectors to slide only radially along the brake drum, the centrifugal member is connected to the mounting platform, and an active cavity for the centrifugal member to move is reserved in the inner cavity of the mounting seat.

[0013] Furthermore, a partition parallel to the mounting platform is fixedly connected to the mounting seat, the movable cavity is located on a side of the partition away from the mounting platform, and the reset member is arranged between the mounting platform and the partition;

[0014] When the probe of the displacement detector is received in the mounting seat, the reset element is in a compressed state.

[0015] Furthermore, a connecting rod aligned with the centrifugal component is fixedly connected to the mounting platform, a through hole corresponding to the connecting rod is penetrated through the partition, a pull rope with one end passing through the through hole and fixed to the connecting rod is fixed to the centrifugal component, and the diameter of the through hole is larger than the outer diameter of the connecting rod and smaller than the outer diameter of the centrifugal component.

[0016] Furthermore, a sealing plate for sealing the detection slot is movably provided in the mounting seat, and a self-opening and closing component is connected between the sealing plate and the mounting platform;

[0017] The self-opening and closing component is configured as follows: when the mounting platform drives the probe of the displacement detector thereon to be retracted into the mounting seat, the self-opening and closing component drives the sealing plate to block the detection slot; when the mounting platform drives the probe of the displacement detector thereon to extend out of the detection slot, the self-opening and closing component drives the sealing plate to release the blockage of the detection slot.

[0018] Furthermore, the self-opening and closing assembly comprises a folding rod with an obtuse folding angle and a bending portion hinged in the mounting seat, one end of the folding rod is movably hinged to the mounting platform, and the other end is connected to the sealing plate;

[0019] When the mounting platform drives the probe of the displacement detector to be retracted into the mounting seat, the folding rod is turned over to the sealing plate to seal the detection slot.

[0020] Furthermore, a sponge layer is provided on a side of the sealing plate close to the displacement detector.

[0021] Furthermore, the brake drum has a detection concave area sunken outwardly on the inner side wall corresponding to the detection groove, the detection groove is opened on the detection concave area, and the edge of the detection concave area has a smooth transition.

[0022] Furthermore, a counterweight block is fixedly connected to the outer periphery of the brake drum and is arranged opposite to the mounting seat, and the total weight of the mounting seat, the control mechanism and the plurality of displacement detectors matches the weight of the counterweight block.

[0023] In summary, the beneficial technical effects of this application are:

[0024] 1. When testing the braking performance of the brake shoe, the brake drum can be driven to rotate to a preset initial rotation speed and detected by the speed detector. The main controller controls the drive motor to shut down on the one hand, and controls the servo cylinder to work on the other hand so that the hydraulic cylinder loads oil pressure to drive the brake shoe to be tested for braking. At the same time, it also controls the timer to start timing. When the brake drum stops rotating under the braking of the brake shoe to be tested, the timer stops timing; at this time, the braking time of the brake shoe to be tested under the set initial speed and the set braking oil pressure can be obtained. Correspondingly, the set initial speed and the set braking oil pressure can also be changed and tested. In addition, during the braking process, the servo cylinder can be controlled to work continuously or intermittently to simulate long braking and inching braking states. At the same time, during the braking test process, the temperature and humidity of the environment in which the brake shoe to be tested is located can also be changed with the help of a temperature and humidity adjustment device to simulate various working conditions of the brake shoe in actual vehicle use to the maximum extent, so as to detect the braking performance of the brake shoe to be tested as comprehensively as possible;

[0025] 2. After the braking time test of the brake shoe to be tested is completed, the control mechanism drives the probes of multiple displacement detectors to contact the surface of the brake shoe to be tested, and then the driving motor drives the brake drum to rotate forward and reverse at a low speed. The angle sensor is used to locate the rotation angle of the brake drum. For example, the angle when the brake drum is rotated to align the displacement detector probe on it with the midline of the two brake shoes to be tested is set to 0°, and then the rotation angle of the brake drum is used as the x-axis, and the displacement detected by the displacement detector is used as the y-axis to draw a displacement curve. By comparing it with the displacement curve in the initial state of the brake shoe to be tested, the actual wear amount of each point of the brake shoe to be tested can be intuitively obtained. Moreover, this detection process can be carried out after each braking is completed, and the detection results are obtained immediately without disassembling the brake shoe. The detection efficiency and accuracy of the detection results are extremely high, which can provide comprehensive and accurate detection data support for the braking performance detection of the brake shoe;

[0026] 3. By installing multiple displacement detectors on the mounting platform and connecting the mounting platform with the centrifugal part through a pull rope, when the brake drum rotates, the centrifugal force of the centrifugal part can be used to drive the probe of the displacement detector on the mounting platform to retract into the mounting seat, so as to prevent the brake shoe from wearing the probe when braking the brake drum; at the same time, when the mounting platform moves, the folding rod is flipped to make the sealing plate block the detection groove, so as to prevent the high-temperature powder of the brake shoe from damaging the displacement detector; when the brake drum is braked to stop, the centrifugal force of the centrifugal part is lost, and the mounting platform drives the probe of the displacement detector to collide with the wear surface of the brake shoe under the action of the reset part, so that the wear amount of the brake shoe can be directly detected, the detection is more immediate, and the detection efficiency is more outstanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0028] Figure 2 This is a schematic diagram of a partial cross-sectional structure of an embodiment of the present application after the detection box body is hidden;

[0029] Figure 3 It is a partial cross-sectional structural schematic diagram mainly used to show the control mechanism of the embodiment of the present application;

[0030] Figure 4 yes Figure 2 Enlarged schematic diagram of part A.

[0031] Description of reference numerals:

[0032] 11. Brake shoe; 12. Hydraulic cylinder; 13. Hydraulic pipeline; 14. Servo cylinder;

[0033] 2. Brake drum; 21. Drive shaft; 22. Drive motor; 23. Speed ​​detector; 24. Angle sensor; 25. Displacement detector; 261. Detection slot;

[0034] 3. Test box; 31. Temperature and humidity adjustment device; 32. Base;

[0035] 4. Mounting seat; 41. Mounting platform; 411. Connecting rod; 412. Pull rope; 42. Reset member; 431. Guide member; 432. Centrifugal member; 44. Active cavity; 45. Partition plate; 451. Perforation;

[0036] 51, sealing plate; 511, sponge layer; 52, folding rod;

[0037] 6. Counterweight. DETAILED DESCRIPTION

[0038] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0039] The present application embodiment discloses a brake shoe pressure control detection system that can simulate an environment. Figure 1 and Figure 2A brake shoe pressure control detection system capable of simulating an environment includes a hydraulic cylinder 12 for controlling a brake shoe 11 to be tested, a hydraulic pipeline 13 connected to the hydraulic cylinder 12, and a servo cylinder 14 for outputting or releasing the hydraulic oil in the hydraulic pipeline 13 to the hydraulic cylinder 12. Specifically, the hydraulic pipeline 13 includes a hydraulic oil tank, an oil pipe, an oil pressure gauge, a pressure-maintaining valve, etc. The hydraulic oil in the hydraulic oil tank can be input into the hydraulic cylinder 12 by controlling the extension and retraction of the piston rod of the servo cylinder 14 to achieve braking action; and according to the different extension lengths of the piston rod of the servo cylinder 14, braking can also be achieved with different oil pressures, i.e., braking forces. The related technologies are all well-known technologies and will not be described in detail here.

[0040] The detection system also includes a test box 3, a temperature and humidity adjustment device 31 and a base 32 for mounting the brake shoe 11 to be tested, and the base 32 is placed in the test box 3; the temperature and humidity adjustment device 31 can be specifically divided into a temperature adjustment device and a humidity adjustment device, which can adjust the temperature and humidity in the test box 3 or at the brake shoe 11 to be tested, which has been recorded in the relevant technology and will not be repeated here.

[0041] In addition, refer to Figure 1 and Figure 2 A brake drum 2 used in conjunction with the brake shoe 11 to be tested is rotatably installed in the test box 3, and a drive shaft 21 extending to the outside of the test box 3 is coaxially fixed to the brake drum 2. Specifically, the brake drum 2 can be detachably installed on the drive shaft 21 to facilitate the installation of the brake shoe 11 to be tested on the base 32; a drive motor 22 for driving the drive shaft 21 to rotate, a speed detector 23 for detecting the rotation speed of the drive shaft 21, and an angle sensor 24 for detecting the rotation angle of the drive shaft 21 are arranged outside the test box 3.

[0042] The speed detector 23 and the servo cylinder 14 are connected to a master controller. The master controller is configured to control the servo cylinder 14 to supply hydraulic oil of a set oil pressure to the hydraulic cylinder 12 and release the power transmission from the drive motor 22 to the drive shaft 21 when the speed detector 23 detects that the rotation speed of the drive shaft 21 reaches a preset value. Specifically, an electric clutch may be arranged between the output shaft of the drive motor 22 and the drive shaft 21. After the electric clutch is connected to the master controller, the power transmission from the drive motor 22 to the drive shaft 21 may be released while the brake shoe 11 is braking, so as to avoid damage to the drive motor 22 after the brake drum 2 is braked; or the drive motor 22 may be directly controlled to be turned off. If the preset detection speed is relatively low, the second method may be selected; if the preset detection speed is relatively high, the first method may be selected to reduce the time for the brake drum 2 to recover the detection speed after being braked, so as to improve the detection efficiency; in this embodiment, the second method is selected, and the master controller controls the drive motor 22 to be turned off.

[0043] Furthermore, the main controller is also connected to a timer, which is configured to record the braking duration from the time when the servo cylinder 14 is controlled to work to the time when the speed detector 23 detects that the rotation speed of the drive shaft 21 is zero.

[0044] Reference Figure 3 The brake drum 2 is embedded with multiple displacement detectors 25 pointing to the surface of the brake shoe 11 to be tested, and the brake drum 2 is provided with a control mechanism for driving the probes of the multiple displacement detectors 25 to contact the surface of the brake shoe 11 to be tested when the brake drum 2 stops rotating.

[0045] After such arrangement, when the brake performance of the brake shoe 11 is tested, the brake shoe 11 can be installed on the base 32, and the hydraulic cylinder 12 can be well matched with the brake shoe 11 to be tested, and then the brake drum 2 on the drive shaft 21 can be fixed. First, the drive motor 22 is used to drive the drive shaft 21 to rotate to the preset initial rotation speed of the brake drum 2. After the speed detector detects that the speed value reaches the standard, the main controller controls the drive motor 22 to shut down on the one hand, and controls the servo cylinder 14 to work on the other hand so that the hydraulic cylinder 12 loads oil pressure to drive the brake shoe 11 to be tested to brake, and also controls the timer to start timing. When the brake drum 2 stops rotating under the braking of the brake shoe 11 to be tested, the timer stops timing; at this time, the braking time of the brake shoe 11 to be tested under the set initial speed and the set braking oil pressure can be obtained. Correspondingly, the set initial speed and brake oil pressure can also be changed and tested. Moreover, during the braking process, the servo cylinder 14 can be controlled to work continuously or intermittently to simulate long braking and inching braking states. At the same time, during the braking detection process, the ambient temperature and humidity of the brake shoe 11 to be tested can be changed with the help of the temperature and humidity adjustment device 31 to simulate various working conditions of the brake shoe 11 in actual vehicle use to the maximum extent, so as to detect the braking performance of the brake shoe 11 to be tested as comprehensively as possible.

[0046] After the braking time detection of the brake shoe 11 to be tested is completed, the control mechanism drives the probes of multiple displacement detectors 25 to contact the surface of the brake shoe 11 to be tested, and then the driving motor 22 drives the brake drum 2 to rotate forward and reverse at a low speed. The angle sensor 24 is used to locate the rotation angle of the brake drum 2. For example, the angle when the brake drum 2 is rotated to align the probe of the displacement detector 25 on it with the midline of the two brake shoes 11 to be tested is set as 0°, and then the rotation angle of the brake drum 2 is used as the x-axis and the displacement detected by the displacement detector 25 is used as the y-axis to draw a displacement curve. By comparing it with the displacement curve in the initial state of the brake shoe 11 to be tested, the actual wear amount of each point of the brake shoe 11 to be tested can be intuitively obtained. Moreover, this detection process can be carried out after each braking is completed, and the detection result is obtained immediately, and there is no need to disassemble the brake shoe 11. The detection efficiency and the accuracy of the detection result are extremely high, which can provide comprehensive and accurate detection data support for the braking performance detection of the brake shoe 11.

[0047] Specifically, refer to Figure 2 and Figure 3 The inner arc side of the brake drum 2 is provided with a detection groove 261, and the outer arc side is fixedly connected with a mounting seat 4 connected with the detection groove 261. The detection groove 261 is a strip groove and is arranged along the width direction of the brake shoe 11 to be tested. The mounting seat 4 is a shell-shaped body with one end open, and its open end is fixedly connected to the outer arc wall of the brake drum 2. The control mechanism includes a mounting platform 41 movably arranged in the mounting seat 4, and a plurality of displacement detectors 25 are sequentially fixedly connected to the mounting platform 41 along the width direction of the brake shoe 11 to be tested. The mounting seat 4 is provided with a control component for driving the mounting platform 41 to move in a direction away from the middle of the brake drum 2 when the brake drum 2 rotates, and a reset member 42 for driving the mounting platform 41 to reset when the brake drum 2 stops rotating.

[0048] Among them, the control component includes a guide member 431 and a centrifugal member 432. The centrifugal member 432 is a solid metal ball or a plastic ball. The guide member 431 is used to limit the multiple displacement detectors 25 so that they only slide radially along the brake drum 2. The centrifugal member 432 is connected to the mounting platform 41. The inner cavity of the mounting seat 4 is reserved with an active cavity 44 for the centrifugal member 432 to move away from the central axis of the brake drum 2. When the brake drum 2 rotates at a low speed, the centrifugal force on the centrifugal member 432 is greater than the deformation force of the reset member 42.

[0049] A partition 45 parallel to the mounting platform 41 is fixedly connected in the mounting seat 4, the movable cavity 44 is located on the side of the partition 45 away from the mounting platform 41, and the reset member 42 is arranged between the mounting platform 41 and the partition 45; when the probe of the displacement detector 25 is received in the mounting seat 4, the reset member 42 is in a compressed state. Specifically, the guide member 431 is set as a guide rod with one end fixed on the mounting platform 41 and the other end sliding through the partition 45. The guide member 431 is provided with two and arranged on both sides of the length direction of the mounting platform 41. The reset member 42 is set as a spring sleeved on the guide member 431, and one end of the reset member 42 contacts the mounting platform 41 and the other end contacts the partition 45.

[0050] Thus, when the brake drum 2 rotates under the drive of the driving motor 22, the centrifugal member 432 moves in the movable chamber 44 in a direction away from the central axis of the brake drum 2 and basically maintains this state; at the same time, the centrifugal member 432 drives the mounting platform 41 to move in the same direction, so that the probes of the multiple displacement detectors 25 on the mounting platform 41 are retracted into the mounting seat 4, and at this time, both sets of reset members 42 are compressed and deformed, thereby effectively preventing the brake shoe 11 from causing wear to the probes of the displacement detector 25 when braking the brake drum 2. When the speed of the brake drum 2 decreases until it stops after being braked, the centrifugal member 432 is no longer subjected to centrifugal force, and the mounting platform 41, under the deformation force of the two reset members 42, smoothly approaches the brake shoe 11, so that the probes of the displacement detector 25 on it pass through the detection groove 261 and abut against the surface of the brake shoe 11, thereby slowly rotating the brake drum 2, and the wear amount of the brake shoe 11 can be detected by the displacement detector 25.

[0051] Considering that the centrifugal member 432 has a large dead weight when the brake drum 2 rotates at a low speed, the stability of the mounting platform 41 may be affected, so that the probe of the displacement detector 25 may shake or even extend out of the detection slot 261 and be scratched by the brake shoe 11.

[0052] For this purpose, refer to Figure 3 and Figure 4 A connecting rod 411 aligned with the centrifugal member 432 is fixedly connected to the mounting platform 41, and the connecting rod 411 is located between the two guide members 431. A through hole 451 corresponding to the connecting rod 411 is penetrated through the partition 45. A pull rope 412 with one end passing through the through hole 451 and fixed to the connecting rod 411 is fixedly connected to the centrifugal member 432. The pull rope 412 is a rigid rope and cannot undergo elastic deformation. The aperture of the through hole 451 is larger than the outer diameter of the connecting rod 411 and smaller than the outer diameter of the centrifugal member 432; and the cavity wall of the movable cavity 44 on the side away from the partition 45 is an arc surface with the center of the through hole 451 on the partition 45 as the center of the circle.

[0053] In this way, when the speed of the brake drum 2 is reduced after being braked, the centrifugal force exerted on the centrifugal member 432 needs to resist its own gravity, so the centrifugal member 432 will swing in the active cavity 44. With the help of the setting of the curved cavity wall on the active cavity 44 and the connection between the centrifugal member 432 and the connecting rod 411 through the pull rope 412, the swing of the centrifugal member 432 has less effect on the mounting platform 41, so that the stability of the displacement detector 25 on the mounting platform 41 can be ensured as much as possible to reduce the possibility of damage to the probe on the displacement detector 25.

[0054] Furthermore, in order to prevent the high-temperature powder of the brake shoe 11 from affecting the displacement detector on the mounting platform 41 during the process of the brake shoe 11 braking the brake drum 2. Figure 3 and Figure 4A sealing plate 51 for sealing the detection groove 261 is movably arranged in the mounting seat 4, a sponge layer 511 is arranged on one side of the sealing plate 51 close to the displacement detector 25, and a self-opening and closing component is connected between the sealing plate 51 and the mounting platform 41.

[0055] The self-opening and closing component is configured as follows: when the mounting platform 41 drives the probe of the displacement detector 25 thereon to be retracted into the mounting seat 4, the self-opening and closing component drives the sealing plate 51 to block the detection slot 261; when the mounting platform 41 drives the probe of the displacement detector 25 thereon to extend out of the detection slot 261, the self-opening and closing component drives the sealing plate 51 to release the blockage of the detection slot 261.

[0056] Specifically, the self-opening and closing assembly includes a folding rod 52 with an obtuse folding angle and a folding portion hinged in the mounting seat 4, one end of the folding rod 52 is hinged to the mounting platform 41, and the other end is connected to the sealing plate 51, and the inner folding angle of the folding rod 52 faces the detection groove 261; when the mounting platform 41 drives the probe of the displacement detector 25 to be retracted into the mounting seat 4, the folding rod 52 flips to the sealing plate 51 to block the detection groove 261. Among them, the folding rod 52 and the mounting platform 41 are hinged in the form of a connecting rod hinged between the two, and the connecting rod can be a straight rod or a curved rod.

[0057] In this way, when the mounting platform 41 moves toward the direction approaching the active chamber 44 driven by the centrifugal member 432, the mounting platform 41 is flipped on the mounting seat 4 through the folding rod 52, so that the sealing plate 51 moves to block the detection groove 261, which can effectively prevent the wear powder of the brake shoe 11 from entering the mounting seat 4 and causing damage to the displacement detector 25; and at this time, the sponge layer 511 on the sealing plate 51 can not only protect the probe of the displacement detector 25, but also clean the probe tip end of the displacement detector 25, especially after the speed of the brake drum 2 is reduced, the probe of the displacement detector 25 follows the movement of the mounting platform 41 and is about to penetrate the detection groove 261. The end of the probe slides on the sponge layer 511, and part of the powder adhered to the probe tip end when it collides with the worn brake shoe 11 can be cleaned off.

[0058] In addition, in another feasible embodiment, in order to prevent the brake shoe 11 from scratching the edge of the detection groove 261 when the brake shoe 11 moves relative to the brake drum 2, which may cause abnormal wear to the brake shoe 11, a detection recessed area is recessed outward on the inner wall of the brake drum 2 corresponding to the detection groove 261, and the detection groove 261 is opened on the detection recessed area, and the edge of the detection recessed area has a smooth transition; or a chamfer may be set on the edge of the notch of the detection groove 261 close to the brake shoe 11, which can also achieve the same effect.

[0059] In addition, in order to avoid abnormal wear of the brake shoe 11 caused by the vibration of the brake drum 2 during rotation after the brake shoe 11 wear detection module is installed on the brake drum 2, which affects the detection result, refer to Figure 2A counterweight block 6 is further fixedly connected to the outer peripheral wall of the brake drum 2 and is arranged opposite to the mounting seat 4. The total weight of the mounting seat 4, the control mechanism and multiple displacement detectors 25 is matched with the weight of the counterweight block 6 to ensure that the dynamic balance of the brake drum 2 during rotation meets the standard.

[0060] The implementation principle of a brake shoe pressure control detection system capable of simulating an environment in the present application is as follows:

[0061] When testing the braking performance of the brake shoe 11, the driving motor 22 is first used to drive the driving shaft 21 to rotate to the preset initial rotation speed of the brake drum 2 and the speed detector detects that the speed value reaches the standard. The main controller controls the driving motor 22 to shut down on the one hand, and controls the servo cylinder 14 to work on the other hand so that the hydraulic cylinder 12 drives the brake shoe 11 to be tested to brake, and controls the timer to start timing. When the brake drum 2 stops rotating under the braking of the brake shoe 11 to be tested, the timer stops timing; at this time, the braking time of the brake shoe 11 to be tested under the set initial speed and the set braking force can be obtained. Correspondingly, the set initial speed and the set braking force can also be changed and tested. In addition, during the braking process, the servo cylinder 14 can also be controlled to work continuously or intermittently to simulate the long braking and inching braking states; at the same time, during the braking test process, the temperature and humidity of the environment where the brake shoe 11 to be tested is located can also be changed by means of the temperature and humidity adjustment device 31 to maximize the simulation of various working conditions of the brake shoe 11 in actual vehicle use, so as to detect the braking performance of the brake shoe 11 to be tested as comprehensively as possible.

[0062] After the braking time detection of the brake shoe 11 to be tested is completed, the control mechanism drives the probes of multiple displacement detectors 25 to contact the surface of the brake shoe 11 to be tested, and then the driving motor 22 drives the brake drum 2 to rotate forward and reverse at a low speed. The angle sensor 24 is used to locate the rotation angle of the brake drum 2. For example, the angle when the brake drum 2 is rotated to align the probe of the displacement detector 25 on it with the midline of the two brake shoes 11 to be tested is set as 0°, and then the rotation angle of the brake drum 2 is used as the x-axis and the displacement detected by the displacement detector 25 is used as the y-axis to draw a displacement curve. By comparing it with the displacement curve in the initial state of the brake shoe 11 to be tested, the actual wear amount of each point of the brake shoe 11 to be tested can be intuitively obtained. Moreover, this detection process can be carried out after each braking is completed, and the detection result is obtained immediately, and there is no need to disassemble the brake shoe 11. The detection efficiency and the accuracy of the detection result are extremely high, which can provide comprehensive and accurate detection data support for the braking performance detection of the brake shoe 11.

[0063] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. The words "first", "second", "third" and similar words used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "One" or "one" and similar words do not indicate a quantitative limit, but indicate that there is at least one. "Include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0064] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A brake shoe pressure control detection system capable of simulating an environment, characterized in that: The invention comprises a hydraulic cylinder (12) for controlling a brake shoe (11) to be tested, a hydraulic pipeline (13) connected to the hydraulic cylinder (12), and a servo cylinder (14) for outputting or releasing hydraulic oil in the hydraulic pipeline (13) to the hydraulic cylinder (12), and also comprises a test box (3), a temperature and humidity adjustment device (31), and a base (32) for mounting the brake shoe (11) to be tested, wherein the base (32) is placed in the test box (3), and is characterized in that a brake drum (2) for use with the brake shoe (11) to be tested is rotatably mounted in the test box (3), a drive shaft (21) extending to the outside of the test box (3) is coaxially fixedly connected to the brake drum (2), and a drive motor (22) for driving the drive shaft (21) to rotate, a rotation speed detector (23) for detecting the rotation speed of the drive shaft (21), and an angle sensor (24) for detecting the rotation angle of the drive shaft (21) are arranged outside the test box (3); The rotation speed detector (23) and the servo cylinder (14) are connected to a master controller, and the master controller is configured to control the servo cylinder (14) to supply hydraulic oil of a set oil pressure to the hydraulic cylinder (12) when the rotation speed detector (23) detects that the rotation speed of the drive shaft (21) reaches a preset value, and at the same time release the power transmission from the drive motor (22) to the drive shaft (21); The master controller is also connected to a timer, the timer being configured to record the braking duration from the time when the servo cylinder (14) is controlled to work to the time when the rotation speed detector (23) detects that the rotation speed of the drive shaft (21) is zero; The brake drum (2) is embedded with a plurality of displacement detectors (25) pointing toward the surface of the brake shoe (11) to be tested, and the brake drum (2) is provided with a control mechanism for driving the probes of the plurality of displacement detectors (25) to contact the surface of the brake shoe (11) to be tested when the brake drum (2) stops rotating; The inner arc side of the brake drum (2) is provided with a detection groove (261) extending therethrough, and the outer arc side is fixedly connected to a mounting seat (4) in communication with the detection groove (261); the control mechanism comprises a mounting platform (41) movably arranged in the mounting seat (4); a plurality of displacement detectors (25) are fixedly connected to the mounting platform (41) along the width direction of the brake shoe (11) to be tested; a control component is arranged in the mounting seat (4) for driving the mounting platform (41) to move in a direction away from the middle of the brake drum (2) when the brake drum (2) rotates, and a reset member (42) for driving the mounting platform (41) to reset when the brake drum (2) stops rotating.

2. A brake shoe pressure control detection system capable of simulating an environment according to claim 1, characterized in that: The control assembly comprises a guide member (431) and a centrifugal member (432); the guide member (431) is used to limit the plurality of displacement detectors (25) so that they slide only radially along the brake drum (2); the centrifugal member (432) is connected to the mounting platform (41); and a movable cavity (44) for the centrifugal member (432) to move is reserved in the inner cavity of the mounting seat (4).

3. A brake shoe pressure control detection system capable of simulating an environment according to claim 2, characterized in that: A partition (45) parallel to the mounting platform (41) is fixedly connected to the mounting seat (4), the movable cavity (44) is located on a side of the partition (45) away from the mounting platform (41), and the reset member (42) is arranged between the mounting platform (41) and the partition (45); When the probe of the displacement detector (25) is received in the mounting seat (4), the reset element (42) is in a compressed state.

4. A brake shoe pressure control detection system capable of simulating an environment according to claim 3, characterized in that: A connecting rod (411) aligned with the centrifugal component (432) is fixedly connected to the mounting platform (41); a through hole (451) corresponding to the connecting rod (411) is penetrated through the partition (45); a pull rope (412) having one end passing through the through hole (451) and fixedly connected to the connecting rod (411) is fixedly connected to the centrifugal component (432); and a hole diameter of the through hole (451) is larger than an outer diameter of the connecting rod (411) and smaller than an outer diameter of the centrifugal component (432).

5. The brake shoe pressure control detection system capable of simulating an environment according to claim 1, characterized in that: A sealing plate (51) for sealing the detection slot (261) is movably disposed in the mounting seat (4), and a self-opening and closing component is connected between the sealing plate (51) and the mounting platform (41); The self-opening and closing component is configured such that: when the mounting platform (41) drives the probe of the displacement detector (25) thereon to be retracted into the mounting seat (4), the self-opening and closing component drives the sealing plate (51) to block the detection slot (261); when the mounting platform (41) drives the probe of the displacement detector (25) thereon to extend out of the detection slot (261), the self-opening and closing component drives the sealing plate (51) to release the blockage of the detection slot (261).

6. A brake shoe pressure control detection system capable of simulating an environment according to claim 5, characterized in that: The self-opening and closing assembly comprises a folding rod (52) having an obtuse folding angle and a bent portion hinged in the mounting seat (4); one end of the folding rod (52) is movably hinged to the mounting platform (41) and the other end is connected to the sealing plate (51); When the mounting platform (41) drives the probe of the displacement detector (25) to be retracted into the mounting seat (4), the folding rod (52) flips over to the sealing plate (51) to seal the detection slot (261).

7. A brake shoe pressure control detection system capable of simulating an environment according to claim 5, characterized in that: A sponge layer (511) is provided on one side of the sealing plate (51) close to the displacement detector (25).

8. The brake shoe pressure control detection system capable of simulating an environment according to claim 1, characterized in that: The brake drum (2) has a detection concave area recessed outwardly on the inner side wall corresponding to the detection groove (261); the detection groove (261) is opened on the detection concave area, and the edge of the detection concave area has a smooth transition.

9. The brake shoe pressure control detection system capable of simulating an environment according to claim 1, characterized in that: A counterweight block (6) is fixedly connected to the outer periphery of the brake drum (2) and is arranged opposite to the mounting seat (4). The total weight of the mounting seat (4), the control mechanism and the plurality of displacement detectors (25) matches the weight of the counterweight block (6).

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